#include<iostream>
using namespace std;

class A{
private:

public:
	static int a;
	A(){}

};

int A::a=100;

class B:public A{
private:
public:

};

int main24(){

	A a1;
	A a2;
	cout<<A::a<<endl;

	A::a=200;
	cout<<A::a<<endl;

	B b1;
	B b2;
	cout<<b1.a<<endl;
	cout<<b2.a<<endl;
	return 0;
}
